Press machines have been proposed that move an upper tool using a vertically moving screw shaft and nut (for example, see Patent Literature 1). In a press machine disclosed in Patent Literature 1, a screw shaft is connected to a first transmission that produces low torque at high speed, and a nut is connected to a second transmission that produces high torque at low speed. The screw shaft is connected to a ram including a holder supporting the upper tool through a co-rotation prevention mechanism. In approaching a workpiece, the press machine regulates the rotation of the nut member and activates the first transmission. Thus, it lowers the ram (upper tool) to a predetermined position at high speed and low torque while rotating the screw shaft. In bending the workpiece, the press machine regulates the rotation of the screw shaft using the co-rotation prevention mechanism and activates the second transmission. Thus, it rotates the nut member to lower the screw shaft at low speed and high torque to move the upper tool to the bottom dead center. It then sandwiches the workpiece between the upper tool and a lower tool and bends the workpiece.